Resilient support and centering arrangement for the electrodes of electric discharge tubes



Nov. 4, 1952 c. ZORGMAN 6 RESILIENT SUPPORT AND CENTERING ARRANGEMENT FOR THE ELECTRODES OF ELECTRIC DISCHARGE TUBES;

Filed June 14, 1949 INVENTOR. CORNELL? ZORGMAN AGENT:

Patented Nov. 4, 1952 RESILIENT SUPPORT AND CENTERING AR- RANGEMENT FOR THE ELECTRODES OF ELECTRIC DISCHARGE TUBES Cornelis Zorgman, Eindhoven, Netherlands, as-

signor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application June 14, 1949, Serial No. 98,979 In the Netherlands June 15, 1948 2 Claims.

This invention relates to electric discharge tubes and more particularly to centering members for the electrodes of such tubes.

As a rule, each electrode is centered at at least one extremity by means of one or more plateshaped insulating members, usually consisting of mica. In order to avoid play of the electrode parts supported in apertures of the said members, such as supporting wires or the extremity of an indirectly heated cathode, it has been suggested to superpose two or more plate-shaped insulating members in such manner as to clamp the electrode parts in position in the apertures or between these members. However, a disadvantage of these known constructions is that resilient clamping is diflicult to ensure. Resilient clamping is very desirable, however, in view of the thermal expansion of the electrodes and for avoiding microphonic disturbances. Consequently, such members must, as a rule, satisfy stringent requirements as to dimensions, very small tolerances being permissible in order to avoid the clamping being too loose or too rigid.

In U. S. Patent #2,494,853 issued January 17, 1950, there is described and claimed an electric discharge tube comprising an electrode system, in which two or more electrodes are centred by means of at least one plate-shaped insulating member consisting of an assembly of two or more parts partly overlapping each other, and are clamped between these parts, characterized in that this clamping is effected by furnishing one of the component insulating parts with tongues, some of which each engage part of an electrode in one direction and one or more other tongues resiliently engage parts of another electrode in the opposite direction, at least one of the tongues having a length such that, when it is bent out of the plane of the plate-shaped part, it engages the associated electrode part. As a rule, the tongues thus engage the associated electrode parts on one side.

However, it has been found that, more particularly if the long tongue engages on one side the extremity of the cathode, it is possible that the cathode may in time become permanently deformed.

The object of the present invention is to mitigate this disadvantage. According to the invention such as electric discharge tube is characterized in that one of the component insulating parts comprises two opposing tongues which engage a part of an electrode and which have a length such that, when bent out of the plane of the plate-shaped part, they engage said part of said electrode. A resilient support is thus provided and a simplification in the shape of the insulatin member is possible, since due to the fact that the two long tongues keep one another in equilibrium, the other, non-resilient tongues may be substituted by a slot with straight sides be tween which the grid supports may be clamped.

The invention will now be explained more fully by reference to the accompanying drawing given by way of example, in which Fig. 1 is a plan view and Fig. 2 is a side-view of an insulating member for use in an electric discharge tube according to the invention.

In the figures, l is the cathode, 2, 3 and 4 sup-- porting rods for grid electrodes which are supported by a normally shaped centering member 7 5. The centering member 5 is provided with conventional circular apertures for the cathode and the supportin rods for the other electrodes.

On the centerin member 5 is positioned an insulating member 6 which comprises two long tongues I and 8 which engage the cathode I at opposite points thereof. The member 6 further has a slot system 9, parallel sides of which rigidly clamp the grid support wires 2 and 3 in position and which slot system 9 is such as to provide the tongues I and 8. When the member 6 is in position, the tongues I and 8 engage the cathode in an inclined manner (Fig. 2) so that a very resilient and reproducible support is provided and, furthermore, the member 6 is prevented by the tongues I and 8 from sliding upwards. As a rule, however, sliding upwards will be prevented by preventing such movement of the insulating member 6, for example by means of flanged edges of the anode or in any other known manner.

What I claim is:

1. In an electric discharge tube, a supporting structure for electrodes therein comprising a support rod and a composite plate shaped insulating member engaging the support rod and comprising a first planar plate-like portion apertured to receive the support rod and a second plate-like portion superimposed upon said first portion and having two opposing flexible tongues each having a length such that it engages the support rod when the tongue is bent out of the plane of the plate shaped member.

2. In an electric discharge tube, a supporting structure for electrodes therein comprising a support rod for a cathode and a composite plate shaped insulating member engaging the support rod and comprising a first planar plate-like portion apertured to receive the support rod and a second plate-like portion superimposed upon said first portion and having two flexible opposing tongues each having a length such that it engages the cathode when the tongue is bent out of the plane of the plate shaped member.

CORNELIS ZORGMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,967,208 Krahl July 1'7, 1934 2,048,257 Glauber July 21, 1936 2,494,853 Alma Jan. 1'7, 1950 

